Local circuit for telegraphs



(No Model.) 2 S heetsSheet I.

B. E. J. EILS.

LOCAL CIRCUIT FOR TELEGRAPHS.

No. 305,906. 4 Patented Sept. 30, 1884.

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B. E. LEILS. LOCAL CIRCUIT FOR TELEGRAPHS.

No. 305,906. Patented Sept 30, 1884.,

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UNITE o BETTE E. J. EILS, OF X VASHIN GTON, DISTRICT OF COLUMBIA.

LOCAL ClRCUIT FO R TELEGRAPHS.

JPECIFICATION forming part of Letters P atent No. 305,906, dated September 30, 1884.

Application filed January 28, 1884. (No model.)

To aZZ whom it may concern:

Be it known that I, BETTE E. J. Bus, acitizen of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in Local Circuits for Telegraphic and other Electrical Circuits; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention, although it may be applied to electric telegraphs in general, as well as to other electric circuits, is more especially dcsigned for use on the so-called neutral side of such diplex, quadruplex, or multiplex telegraphs in which one message is transmitted by changes in the polarity of the line-current and received through a polarized relay, and another message is transmitted by changes in the strength of the linecurrent irrespective of its polarity, and received through a Morse or neutral relay, the polarized relay and the 'local circuit controlled thereby being com monly called the polar side of such telegraphs, while the neutral relay, in connection with the local circuit controlled by it, is commonly called the neutral side. In these telegraphs the neutral relay is subject to reversals of the direction of the line-current, which cause a momentary demagnetization of such relay, and result in inutilat-ions of the signals passing through the relay at the time unless some means is provided in the local circuit or connections to bridge over these moments of demagnetization.

My improved local circuit is peculiarly valuable when applied to the neutral side of such telegraphs for the simultaneous transmission of several messages, because it is capable of bridging over the moments of demagnetization due to reversals of the direction of the linecurrent. I

invention consists, primarily, of a normally-open main local circuit provided with a branch circuit, which is automatically closed by the sounder on the closing of the main local circuit by the armature-lever of the relay, and by which the magnetization of the sounderunagnet is maintained after the opening of the main circuit by the relay.

It further consists ofa local circuit organized as just explained and provided, in addition, with a second branch circuit, which is closed, at the end of each signal, through the back contact of the relay, to neutralize the current in the again by the armature-lever of the sounder.

Figure 1 of the annexed drawings is a diagram of my invention, showing a neutral relocal circuit. my invention.

The relay B has afront contactscrew, a, and a back contact-screw, a which are insulated from each other, and between which the arniatu re-lcver c of the relay plays, said lever being normally held against the back contactscrcw, a by the usual retractile spring. One pole of the local battery L B is connected by wire 1 with the front contactscrew, a, of the relay. The other pole of said battery is connected by wire 2 to one end of the helix 8 of the sounder S, the other end of which helix is connected by wire 3 to armature-lever c of the relay. The armature-lever b of the sounder plays between the insulated back stop, I), and the front contact-screw, Z2, and is connected by wire at with wire 1 at post 5. Front contact-screw, If, of the sounder is connected by wire 6 with wire 3 at post 7. The soundermagnet is wound with a second helix, 5, one end of which is connected by wire 8 with wire 2 at post 9, while the other end is connected by wire 10 with the back contact-screw, c of the relay. The helices s and s are wound on the core in oppositedirections, and are of equal capacity, so that the sounder-magnet is what is usually termed a differential electro-niagnet. \Vhcn the armature-lever of the relay rest-s against the back contact-screw, a, the main local circuit is open, as well as its two branch circuits. When the relay attracts its armature, and thus puts lever to in contact with the front contact-screw, a, the main local circuit is closed and a current flows through helix 5 of the sounder. Its armature-lever b promptly moves forward, and on striking front Fig. 2 shows a modification of first branch circuit, but is immediately opened lay of a telegraph controlling niy improved contact-screw, b closes the branch which ex tends from post 5 to post 7, and includes both said armature-lever and said contact-screw. When the relay-magnet releases the armature, the first effect is to break the main local cir euit; but a closed circuit is still maintained through the branch from post 5 to post 7 ,and the sounder remains unaffected until the relay armature-lever establishes contact with the back contact-screw, (1?. At that moment the second branch, which extends from post 2 to back contact-screw, a and includes helix 8, is closed. Immediately the current flowing through helix 8 is neutralized by the current flowing through helix 8 in a reverse direction, the sounder-magnet releases its armature, and simultaneously both branch circuits are broken by the retraction of the sounder armature-lever.

The use of the helix 8 provides for a prompt discharge of the sounder-magnet; but my invention is not limited, primarily to the use of such helix, as my first claim indicates. Other means may be employed instead. 7 For instance, said helix s and wire 10 may be omitted and post 9 connected by wire 8 directly to the back contact-screw, a, of the relay, so as to merely shunt the current around helix 3. This modification is illustrated in Fig. 2. i

I claim as my invention- 1. The combination, substantially as before set forth, of a relay in the main line and a normally-open local circuit having a branch circuit which passes through the front contact and armature-lever of an electro-magnet in said local circuit.

2. The combination, substantially as before set forth, of a relay, a normallybpen local circuit having a branch circuit which passes through the front contact and armature-lever of an electro-m'agnet in said local circuit, and a second branch circuit, which includes a separate helix on said electro-magnet and passes through a portion of the first branch circuit and the back contact and armature-lever of the relay.

In testimony whereof I affix my signature in presence of two witnesses.

B. E. J. EILS.

Witnesses;

O. A. NEALE, E. T. WALKER. 

